Three types of welded tubes are often inspected with ultrasound: Submerged arc welded pipes (SAW pipes) with either longitudinal
or helical weld and electric resistance welded pipes (ERW pipes) with longitudinal weld. This paper will focus on the
online test of ERW pipes.
Initially, the state of the art of conventional multi-channel UT is summarized. Afterwards, recent developments in phased
array UT (PAUT) are presented. The optimization of the phased array probe design and the setup of complex testing configurations
are supported by the CIVA simulation software. Examples of industrial installations of phased array UT using a large
number of parallel channels are described. The technical performance (signal noise ratio, testing speed, ultrasonic coverage,
etc.) of conventional UT and PAUT is compared. Conclusion: There are good arguments to continue with a combination of
the advantages of both worlds.